How to score a perfect three stars on angry birds space world 1 level 21
This level is another rather easy one. Sort of an introductory level for the purple bird. That’s the one that lets you change direction in mid air. If you press down on your screen the bird will fly directly at the place you pushed. All you have to do to get your three stars is shoot the bird into the air above the high tower and as it is straight over it push on ground level beneath it so the bird flies through the wooden bits of the tower. This will in turn make it topple over and take out the pigs in it as well as sending debris on top of the pig in its smaller wooden bunker.
For a better look at how I passed level 1-21 take a look at the video below